According to Forker's "Ammo and Ballistics" book, .45 ACP will have significant drops between 18 and 34 inches at 100 yards (depending on brand, weight, powder, type of bullet), most of the rounds being in the mid 20s.
A .45 is an excellent round, but was not really designed for ranges of 100 yards, but for closer in CQB fighting. The combination of cross section and slower speed sort of reduce its aeronautic abilities to have a flat trajectory over any great distances. Out to 50 yards, drop was between 4 and 7.6 inches. At 25 yards, drop was only 0.9-1.9 inches. There was one exception that must be a typo. PMC 230 gr FMJ ammo was shown with 11.4 inches of drop at 25 yards, but came up on a drop of only 5.6 inches at 50, down to 23.2 at 100. Given that most bullets do not move in a serpentine fashion, it must be a typo at the 25 yard mark and was probably meant to be a 1.4 inch drop.